At the big show, set to air live August 28 on MTV, Katy's celeb-filled video will be up against Adele's "Rolling in the Deep," Bruno Mars' "Grenade," Britney Spears' "Till the World Ends" and Pitbull's "Give Me Everything." So when Rebecca Black heard that Perry's video got a nod, she was super stoked, especially since the viral star also appears in the clip.

"That's really cool," Black told MTV News. "Katy, I've always been really inspired by all of her story. I've always loved her story and just to finally be part of one of my big inspiration's, like, [my] idol's big video, and now it's nominated for a VMA? I couldn't be happier," she gushed. "But I couldn't be happier for her. She dominated the VMA nominations, so it's really cool."

In the video, Black gives Perry's Kathy Beth Terry a makeover, elevating her to party-queen status. And on the video set, Perry gave Black a little music industry advice. "She really just gave me a lot of support, really reassured me," she recalled. "She was very reassuring and kept telling me keep doing what you're doing, don't listen to the haters. I mean, a lot of people have told me that, but coming from one of my idols that really gave me an impact, that really gave me that reassurance that I really needed.

"She's got this presence about her that is so comforting because she's so, she's not intimidating. She's just like a big sister," she added. "She's so gorgeous, but she's not that popular girl in school that no one can talk to because she thinks she's better than everyone. She's humble, she's down to earth."

You can vote for general VMA categories, including Best New Artist, by visiting VMA.MTV.com or m.mtv.com on your mobile phone. In addition, you can get in on Best New Artist text voting by texting BNA to 66333 on your wireless phone. Voting continues through the show, which airs live August 28 at 9 p.m. ET. (Verizon subscribers can vote on all categories via SMS by texting VMA to 66333; standard message rates apply.)

The 28th annual MTV Video Music Awards will air live on Sunday, August 28, from the Nokia Theatre in Los Angeles at 9 p.m. ET/PT. See the list of nominees, revisit last year's highlights and vote for your favorites in the general categories by visiting VMA.MTV.com.